A(nonrotating) star collaps onto from an initial radius `R_(i)` with its mass remaining unchanged. Which curve in figure best gives the gravitational acceleration `a_(g)` on the surface of the star as a function of the radius of the star during the collapse?

A (non-rotating) star collapses onto itself from an initial radius R_i , its mass remaining unchanged. Which curve in the figure best gives the gravitational acceleration a_g , on the surface of the star as a function of radius of star during collapse?

A (non-rotating) star collapses onto itself from an initial radius R, its mass remaining unchanged. Which curve in the figure best gives the gravitational acceleration ag on the surface of the star as a function of radius of star during collapse?

A spherical hole of radius R//2 is excavated from the asteroid of mass M as shown in the figure the gravitational acceleration at a point on the surface of the asteroid just above the excavation is

A spherical hole of radius R//2 is excavated from the asteroid of mass M as shown in the figure the gravitational acceleration at a point on the surface of the asteroid just above the excavation is

The kinetic energy needed to project a body of mass m from the earth's surface to infinity is (R is radius of the earth, g is gravitational acceleration on the surface of the earth)

A star of mass M and radius R is made up of gases. The average gravitational pressure compressing the star due to gravitational pull of the gases making up the star depends on R as

Two stars of mass M_(1) & M_(2) are in circular orbits around their centre of mass The star of mass M_(1) has an orbit of radius R_(1) the star of mass M_(2) has an orbit of radius R_(2) (assume that their centre of mass is not acceleration and distance between starts is fixed) (a) Show that the ratio of orbital radii of the two stars equals the reciprocal of the ratio of their masses, that is R_(1)//R_(2) = M_(2)//M_(1) (b) Explain why the two stars have the same orbital period and show that the period T=2pi((R_(1)+R_(2))^(3//2))/(sqrt(G(M_(1)+M_(2)))) .

Two stars of mass M_(1) & M_(2) are in circular orbits around their centre of mass The star of mass M_(1) has an orbit of radius R_(1) the star of mass M_(2) has an orbit of radius R_(2) (assume that their centre of mass is not acceleration and distance between starts is fixed) (a) Show that the ratio of orbital radii of the two stars equals the reciprocal of the ratio of their masses, that is R_(1)//R_(2) = M_(2)//M_(1) (b) Explain why the two stars have the same orbital period and show that the period T=2pi((R_(1)+R_(2))^(3//2))/(sqrt(G(M_(1)+M_(2)))) .

Although a photon has no rest mass, but it possesses the inertial mass m="hf"/c^2 where h is Planck's constant , f is frequency of light and c is speed of light . Since light is deflected by a gravitational field , so it is naturally assured that photons have same gravitational behaviour as other particles. When photon is emitted from source of star of mass M and radius R, total energy of photon will be sum of hf and gravitational potential energy. At a large distance from star, the photon is beyond the star's gravitational field , so its gravitational potential energy becomes zero but its total energy remains constant. So frequency of a photon emitted from surface of a star decreases as it moves away from star. A photon in visible region of spectrum is thus shifted towards red end, and this phenomena is known as gravitational red shift. The potential energy of photon which is at surface of star is (where , M=Mass of the star , R=Radius of the star, G=Universal gravitational constant )